- Offers an auto-locking elevation adjustment for rock-solid reticle adjustment- extended Twilight Lens System optimizes the transmission of low-light wavelengths, so you see the details of low-light scenes in greater, brighter detail than with any other riflescope available- Diamond Coat 2 offers unsurpassed durability while boosting light transmission for greater brightness, clarity, and contrast- 34mm main tube for maximum elevation and windage travel- With the reticle in the front focal plane of the ER/T, the reticle magnifies with the image so you can estimate range using Leupold's Mil Dot or TMR reticles at any magnification setting- Side focus parallax adjustments from 50 yards to infinity, from any shooting position- Multiple adjustment styles with audible, tactile click windage and elevation adjustments- M5 adjustments are calibrated in Mils for easy metric conversion- Flip-open lens covers are standard issue with the Mark 4 ER/T riflescope- H-27 Reticle- Matte Black Finish